PT 15 S1 Q4

Until the 1980s, most scientists believed that non-catastrophic geological ... ...

In the passage, the author is primarily concerned with doing which one of the following?
(A) describing three theories and explaining why the latest of these appears to be the best of the three
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Practice Set: Science & Technology Mix 2